Rituximab for Hypersensitivity Pneumonitis

Clinical Efficacy and Safety

The American College of Chest Physicians recommends considering rituximab as salvage therapy for severe, refractory hypersensitivity pneumonitis, with dosing protocols suggesting 1 gram IV every 2 weeks (×2 doses) or 375 mg/m² weekly for 4 weeks 1, 2
Rituximab may cause drug-induced hypersensitivity pneumonitis and interstitial lung disease, with an incidence of rituximab-induced ILD being 15% fatal in one systematic review of 121 cases 3
The American Academy of Allergy, Asthma, and Immunology describes severe infusion reactions characterized by hypoxia, pulmonary infiltrates, respiratory distress, myocardial infarction, and cardiogenic shock, primarily with first infusion 2, 5
The American College of Chest Physicians highlights critical infectious risks, including fatal sepsis, progressive multifocal leukoencephalopathy, and hepatitis B reactivation, emphasizing the need for hepatitis B screening before treatment 2, 4

The American College of Chest Physicians recommends monitoring protocol, including hepatitis B screening, baseline pulmonary function tests, complete blood count, hepatic and renal function, and pregnancy test if applicable, as well as close monitoring during infusion and serial pulmonary function tests at 6-month intervals 2, 4
Infection surveillance is necessary given profound B-cell depletion, and consideration of Pneumocystis prophylaxis if on concomitant immunosuppression 2, 4